2. Managed Beans Facility

In this step, we will create and configure Managed Beans for the web application. We will create a JavaBean called UserBean that holds information like userId, password, name and contact details.

2.1. Import ContactDetailsBean class

1. In the AppXplorer view locate and open the node workshop-jsf-tutorial > web/WEB-INF/src/java.
   
   
   
2. Create new packages called beans and util under the node web/WEB-INF/src/java by right clicking on the node and choosing New > Package.
3. You have been provided a ContactDetailsBean class. It is a very simple class that holds contact details information like address, city, state, country, zipcode, office and resident phone numbers. Copy the class ContactDetailsBean.java from the folder workshop-JSF-tutorial/web/Resources to beans package. Open and review the code.

2.2. Create a Managed Bean class UserBean

1. Right click on the beans package in the AppXplorer view and choose New > Class
2. Type beans for package name, UserBean for class name. Click Add and enter Serializable so that the java.io.Serializable interface is added to the Interfaces list.

   

3. Click Finish
4. In UserBean class declare variables as shown below:

   private String userId = null; private Integer password = null; private String name = null; private ContactDetailsBean contactDetails = null;

5. Generate getter and setter methods for each variable by selecting Source > Generate Getters and Setters.
6. Save the UserBean class.

2.2.1. Import DataStoreBean and MessageFactory classes

1. From the workshop-JSF-tutorial/web/Resources folder, copy the class DataStoreBean.java to beans package and the class MessageFactory.java to util package.
   
   

The DataStoreBean maintains a list of registered users. Open the class DataStoreBean and review the code. The DataStoreBean constructor initializes instance of java.util.Hashtable to maintain list of registered user. It has methods to add / remove user and get user information. For each user the Hashtable maps userId as a key and a UserBean instance as a value.

The MessageFactory class retrieves localized messages from the application resource bundle, i.e. application.properties file. Open the class and review the code. It has method getMessage(String, Object[ ]) that returns instance of FacesMessage for localized messages. The String argument is the key that corresponds to the message in the ResourceBundle. The Object instance typically contains the substitution parameters that are embedded in the message. It uses the FacesContext to access the Application instance on which the messages are registered.

2.2.2. Implement the method to register a user

In this step you will implement the method registerUser( ) in UserBean class. The method is responsible for adding the user to the data store, retrieving FacesMessage instances for localized messages with the key thanksMsg_Registration, adding it to FacesContext and returning the logical outcome success.

If, the user with the same userId already exists then the method retrieves a FacesMessage instance for a localized message with key userIdExists, adds it to FacesContext and returns null.

1. Copy the following lines of code for the registerUser( ) method into the UserBean class. You can also copy it from the file workshop-JSF-tutorial/web/Typing_Aid/UserBean_registerUser_Method.txt

   public String registerUser( ) {     FacesContext context = FacesContext.getCurrentInstance( );     ExternalContext extContext = context.getExternalContext( );     Map appMap = extContext.getApplicationMap( );     DataStoreBean dataStore = (DataStoreBean)appMap.get(DataStoreBean.DB_NAME);     if(dataStore.getUser(userId) != null) {       Object[ ] objArr = new Object[ ] { userId };       FacesMessage message = MessageFactory.getMessage(context, "userIdExists", objArr);       context.addMessage(null, message);       return null;     } else {       dataStore.addUser(this);       Object[ ] objArr = new Object[ ] { name };       FacesMessage message = MessageFactory.getMessage(context, "thanksMsg_Registration", objArr);       String msg = message.getDetail( );       extContext.getRequestMap( ).put("thanksMsg_Registration", msg);       return "success";     } }

   
   If the user already exists, the method adds a localized message to FacesContext and returns null . This causes the JavaServer Faces implementation to re-render the JSP page with messages and without creating a new view of the page.
2. Add the following import statements:

   import javax.faces.context.FacesContext;
   import javax.faces.context.ExternalContext;
   import java.util.Map;
   import javax.faces.application.FacesMessage;
   import util.MessageFactory;  
     

3. Save the UserBean class.

2.3. Define localized messages

To make the application support multiple languages, we use the internationalization feature. We define text constants, component labels / titles and messages into properties files that are used by the JSF components and Java classes.

The registerUser( ) method of UserBean gets localized messages for the keys userIdExist and thanksMsg_Registration from the application resource bundle file application.properties

1. Open the application.properties file in the WEB-INF/src/java/resources folder; type the following lines and save the file.

userIdExists=The userId {0} already exists, pls. try another userId. thanksMsg_Registration=Dear {0}, Thank you for registering with Workshop

2.4. Configuring Managed Bean

To enable the JSF framework for instantiating backing beans and storing them in the appropriate scope, you must configure it in the application configuration resource file faces-config.xml using the managed-bean XML element. The faces-config.xml file is processed at application startup time. When a page references a bean, the JavaServer Faces implementation initializes it according to its configuration in the application configuration resource file.

The UserBean has a property contactDetails of bean type ContactDetailsBean. Hence, we first define managed-bean configurations for ContactDetailsBean and then for the UserBean.

2.4.1. Declare ContactDetailsBean configuration

1. Open the AppXplorer view, if necessary.
2. Right-click workshop-jsf-tutorial > web > Faces Configuration > Managed Beans and select New Managed Bean…

   

3. In the Managed Bean Tag dialog type contactDetails for the name of the Managed Bean, select Managed Bean class beans.ContactDetailsBean and scope none.
   Click Finish.
   
   



This adds Managed Bean configuration for ContactDetailsBean to faces-config.xml file.

2.4.2. Declare UserBean configurations

1. Right-click Faces Configuration > Managed Beans and select New Managed Bean…

   

2. In Managed Bean Tag dialog type user for name of the Managed Bean, select Managed Bean class beans.UserBean and scope session.



3. Click Next
4. In Managed Bean Tag dialog click the Add… button which opens Managed Property Tag dialog.

   

5. In Managed Property Tag dialog, in the Name field type contactDetails, in the Description field type the text Represents contact information of user and in the Value field type #{contactDetails}.
   
   In the Managed Property Tag dialog click OK.
   
   



This will add managed property contactDetails for managed bean user in Managed Bean Tag dialog.

6. Click Finish in Managed Bean Tag dialog.

   
   
   
   This adds Managed Bean configuration for UserBean to faces-config.xml file.

7. Double-click Faces Configuration > Managed Beans > user
   
   This opens a split-pane source and visual Faces Configuration editor.



The user managed-bean declaration creates a UserBean in Session scope. This bean has property contactDetails that references the contactDetails managed-bean.

The contactDetails managed-bean declaration will not create an instance of ContactDetailsBean because it is defined with the scope none.

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